The invention relates to a traversing device in a plant for manufacturing chains, in particular heavy chains, wherein a carriage for carrying the chain end under production is movable along a guide on at least one side of a rectilinear production line comprising different work stations, such as stations for bending a new link element and introducing same into the previously produced link of the chain, welding the bent link element, trimming the weld, and possibly inserting a support element into the last link thus produced.
Such a traversing device is known from Swedish Pat. No. 7314459-4, wherein the production line is rectilinear and limited on each side by a guide supporting a carriage, these guides being constituted by stationary rails. Each carriage has a chain supporting structure in the form of a crab, which is movable in the transverse direction and permits the carriages to pass each other during the simultaneous manufacture of the two chains.
This arrangement with stationary guides has substantial drawbacks. When the carriage is moved along its stationary rails, strong side forces will be exerted on the crab carrying the chain end by the fed out, ready-made chain, which usually is fed out via a stationary stand to a collecting station. Due to these side forces, the transverse mobility of the crab must either be very limited or the structure must be given very large dimensions, so that the crab and the carriage will resist the forthcoming side forces even when the crab is displaced far away from its central position relative to the rails. However, such dimensioning of the structure is disadvantageous because of increased installation and maintenance costs.
Thus, in the known device, the stationary rails carrying each carriage and the corresponding crab must be placed rather close to the rectilinear production line.
When developing chain manufacturing plants, however, it has proven advantageous to arrange at least one more work station outside the rectilinear production line, e.g., a station for re-orienting the relative position of the recently introduced link element, which should take place between the bending and welding stations (these two stations are normally located at each end of the production line). Further, it is desirable to be able to move the carriage, so that the chain end hanging down therefrom will be transported at a great distance from the production line, whether the work stations are manually or automatically operated.
Particularly in the case of automated work stations, it is furthermore advantageous not to have to hoist and lower the chain end, i.e. to enable the same, in one direction, to freely pass each work station. Although, at each automated station automatic positioning of the last link to be worked takes place, such positioning requires a relatively exact pre-positioning both vertically and sideways. This pre-positioning will of course be facilitated if the chain end merely has to be displaced upwards or downwards in correspondence substantially to the length of one link.